WEBENCH® Tools/BQ27421-G1: BQ27421-G1 is not getting detected with BQStudio

Vidyasagar Kunala

Part Number: BQ27421-G1
Other Parts Discussed in Thread: BQSTUDIO, , EV2400, BQ34Z100

Tool/software: WEBENCH® Design Tools

Hi,

I have connected BQ27421-G1 with BQStudio using EV2400. When I click on BQStudio GUI icon, I'm getting a pop-up asking me to select the device. Even if I select Fuel Gauge & BQ27421-G1, I'm not getting any acknowledgement from the device.

I have used pull-up resistors inside EV2400 for SCL & SDA lines.

I got battery voltage 3.8V at BAT pin & fuel gauge generated 1.8V at its VDD pin. This confirms that fuel gauge is working properly.

I'm using BQStudio v1.3.54.1 & EV2400 v0.18.

I'm not using EVM. I'm working on our design which uses BQ27421-G1 for measuring battery SOC.

I didn't understand what is the issue because of which BQ27421 is not getting detected with BQStudio. Please help in resolving the issue at the earliest.

Thanks & Regards

Vidyasagar Kunala

over 7 years ago

0 Onyx Ahiakwo over 7 years ago

TI__Guru* 76230 points

Hi Vidyasagar,

Can you send a screen shot of the pop up screen that shows when you try starting bqstudio?
Can you also share a schematic of the gauge portion of your device?
Do you have a 10K thermistor connected?
Are you using the i2c port of the ev2400?

thanks
Onyx

0 Vidyasagar Kunala over 7 years ago in reply to Onyx Ahiakwo

Prodigy 200 points

Hi Onyx,

Thanks for quick reply. Due to holidays, I'm replying late. Please find answers to your queries below.

Attached BQStudio openeing screen shot & Schematic of fuel gauge section of our design.

We are using Thermistor inside battery. So no external thermistor used.

I'm using I2C port of EV2400 only.

Let me know if you need any other information. Help me resolve this issue at the earliest.

Thanks & Regards

Vidyasagar

0 Onyx Ahiakwo over 7 years ago in reply to Vidyasagar Kunala

TI__Guru* 76230 points

Hi Vidyasagar,
The 1.8M resistor from BIN pin to ground should not be there. It should be removed. Does VDD measure 1.8V when the battery is applied?
Are you sure your ev2400 is functional?
thanks
Onyx

0 Vidyasagar Kunala over 7 years ago in reply to Onyx Ahiakwo

Prodigy 200 points

Hi Onyx,

We used 1.8M resistor to pull-up BIN pin to VDD. Same was shown in the schematic. This recommendation is given in BQ27421 datasheet for removable battery packs, hence we implemented.
I measured 1.8V on VDD pin of Fuel Gauge.
I used same EV2400 to program another Fuel Gauge(BQ34z100). So I can confirm that there is no issue with EV2400.

Let me know what could be the issue in our case.

Thnaks
Vidyasagar

0 Onyx Ahiakwo over 7 years ago in reply to Vidyasagar Kunala

TI__Guru* 76230 points

Hi Vidyasagar
My apologizes, i thought the 1.8M on was tied to ground. Can you try replacing the IC/. I would also suggest you get an EVM to help your debbugging effort. That way you can compare what the difefernces are betweem signals on the different pins
thanks
Onyx

0 Vidyasagar Kunala over 7 years ago in reply to Onyx Ahiakwo

Prodigy 200 points

Hi Onyx,

I tried on another board, still I got same problem.
But I was able to read Fuel Gauge registers using Microcontroller through I2C.
Not able to understand what is the issue with GUI.
Let me know your inputs on this.

Thanks
Vidyasagar

0 Onyx Ahiakwo over 7 years ago in reply to Vidyasagar Kunala

TI__Guru* 76230 points

There might be an issue with the pull-ups on the com lines. Can you confirm if you are using the ev2300 or ev2400? The ev2400 is suppposed to have pull-ups but the ev2300 doesn't.

thanks
Onyx

0 Onyx Ahiakwo over 7 years ago in reply to Onyx Ahiakwo

TI__Guru* 76230 points

Also, Can you try updating bqstudio to v1.3.86 to see if that changes anything,

0 Vidyasagar Kunala over 7 years ago in reply to Onyx Ahiakwo

Prodigy 200 points

Hi Onyx,
As mentioned earlier, I'm using EV2400 only by removing pull-up resistors on the board.
Thanks
Vidyasagar

0 Vidyasagar Kunala over 7 years ago in reply to Onyx Ahiakwo

Prodigy 200 points

As per TI site, bqstudio v1.3.86 released for testing only. I'm not expecting issue will be solved because of that. But still I will do that when I get time.

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WEBENCH® Tools/BQ27421-G1: BQ27421-G1 is not getting detected with BQStudio